WASHINGTON (MarketWatch) - House Speaker Dennis Hastert on Thursday apologized for the sex scandal surrounding former Rep. Mark Foley, but said he saw no reason to resign his post over the Republican leadership's handling of the matter."I'm deeply sorry that this has happened," Hastert said at a news conference in his Illinois district. "And the bottom line is that we're taking responsibility, because ultimately, as someone has said in Washington before: 'The buck stops here.'"Hastert, however, rejected calls by conservative groups for his resignation. The speaker said he didn't believe that he would undermine the GOP's prospects in the Nov. 7 midterm elections."I said I haven't done anything wrong, obviously," Hastert said.The news conference came minutes after Democratic and Republican members of the House ethics committee announced that they had established a special subcommittee that will investigate the scandal, which broke last Friday with the resignation of Foley, a Florida Republican, who had been questioned by ABC News about sexually explicit Internet messages allegedly sent to teenage boys who had served as congressional pages.The panel has issued dozens of subpoenas for documents and testimony.Hastert welcomed the committee's decision and said he would fully cooperate with the effort. He also called for a criminal investigation by the Justice Department and Florida authorities. Earlier, Hastert announced a toll-free hotline for anyone with relevant information regarding the page program.The House, meanwhile, has "reached out to experts around the country to put a system in place to make sure this never happens again," he said.Polls show Democrats are within striking distance of making a net gain of 15 seats needed to take control of the House. Foley had been expected to easily win re-election to a seventh term. Political handicappers now expect Democrat Tim Mahoney to win the seat.A handful of conservative groups this week urged Hastert to resign the speakership. Democrats and some Republicans charge that Hastert and other GOP officials should have taken steps to investigate the Florida Republican after a teenage former page complained about an e-mail from Foley last year which the teen found to be inappropriate."The problem today is that House Republican leaders had evidence of a sexual predator in their ranks and chose to cover it up instead of choosing to protect these children. What is needed is for Republican leaders to testify under oath about what they knew, when they knew it, and why they didn't properly act," said Senate Minority Leader Harry Reid, D-Nev.Senior Republican lawmakers said Hastert was made aware of the e-mail, which wasn't sexually explicit, in the spring.Hastert says he doesn't recall those conversations, but doesn't dispute that they took place.After being alerted to the e-mail, Rep. John Shimkus, R-Ill., who heads the committee that oversees the page program, told Foley to cease contact with the boy. Hastert, Shimkus and other officials say they had no knowledge of the sexually explicit Internet messages before they were revealed by ABC News last week."Could we have done it better? Could the Page Board have handled it better? In retrospect, probably, yes. But at that time, what we knew and what we acted upon was what we had," Hastert said.Top congressional Republicans closed ranks behind Hastert after the news conference."I continue to have full confidence in Speaker Hastert and his leadership, and I applaud him for his comments today. He has my full support, and I believe strongly he should remain our speaker," said House Majority Leader John Boehner, R-Ohio, the No. 2 House Republican."Mark Foley's actions were despicable, and he deceived us all," said House Majority Whip Roy Blunt of Missouri, No. 3 in the House GOP leadership. "I know that if the speaker had known what we know now about Foley's disgusting activities, he would have personally moved to have Foley expelled from the House of Representatives."Senate Majority Leader Bill Frist, R-Tenn., offered words of support for his House counterpart."Denny Hastert is good man, a capable leader and he has my confidence and support," Frist said.Hastert told the Chicago Tribune in an interview conducted Wednesday night and published Thursday that his resignation would only play into the hands of Democrats."Our members are supportive. I think that [resignation] is exactly what our opponents would like to have happen -- that I'd fold my tent and others would fold our tent and they would sweep the House," Hastert said.Hastert's top lieutenants in the leadership had previously distanced themselves from the speaker's handling of the matter in recent days.On Wednesday, Blunt said he would have handled the matter differently had he been made aware of the e-mail.A day earlier, Boehner told an Ohio radio station that he had been assured by Hastert last spring that the Foley matter had been handled.On Wednesday, Rep. Ron Lewis, R-Ky., who is in the midst of a tough re-election battle, cancelled an upcoming fundraising visit by Hastert. William L. Watts is a reporter for MarketWatch.